Nipple-areolar complex: normal anatomy and benign and malignant processes

The nipple-areolar complex may be affected by many normal variations in embryologic development and breast maturation as well as by abnormal processes of a benign or malignant nature. Benign processes that may affect the nipple-areolar complex include eczema, duct ectasia, periductal mastitis, adenomas, papillomas, leiomyomas, and abscesses; malignant processes include Paget disease, lymphoma, and invasive and noninvasive breast cancers. Radiologists should be aware of the best methods for evaluating each of these entities: Many disorders of the nipple-areolar complex are unique or differ in important ways from those that occur elsewhere in the breast, and they require a diagnostically specific imaging evaluation. Patients may present with benign developmental variations; inversion, retraction, or enlargement of the nipple, which may have either a benign or a malignant cause; a palpable mass; nipple discharge; skin changes in and around the nipple; infection with resultant nipple changes or a subareolar mass; or abnormal findings at routine mammographic screening. Further diagnostic imaging may include repeat mammography, breast ultrasonography, galactography, and magnetic resonance imaging. When skin changes are present, a clinical evaluation by the patient's primary care physician, dermatologist, or surgeon should be part of the diagnostic work-up.